US6623518B2 - Implant delivery system with interlock - Google Patents

Abstract

An implant delivery system includes outer and inner elongated, flexible tubular members each having a distal and proximal end. The outer tubular member is sized to be passed through the body lumen with the distal end advanced to the deployment site and with the proximal end remaining external of the patient's body for manipulation by an operator. The inner tubular member is sized to be received within the outer tubular member. The outer tubular and inner tubular members are axially slidable relative to one another between a transport position and the deploy position. The inner tubular member has an implant attachment location at its distal end. The implant attachment location is covered by the outer tubular member when the inner and outer tubular members are in the transport position. The implant attachment location is exposed when the inner and outer tubular members are in the deploy position. Sliding relative motion between the inner and outer members exposes first a distal end of the implant attachment location and last a proximal end of the stent attachment location. An implant is carried at the implant attachment location. A proximal end of the implant is interlocked with the inner member to be restricted from axial movement relative thereto until the distal end of said outer tubular member moves proximally to the proximal end of the implant attachment location.

Description

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention pertains to a system for delivering an implant to a site in a body lumen. More particularly, this invention pertains to a delivery system for a self-expandable implant such as a stent.

2. Description of the Prior Art

Stents are widely used for supporting a lumen structure in a patient's body. For example, stents may be used to maintain patency of a coronary artery, other blood vessel or other body lumen.

Commonly, stents are commonly metal, tubular structures. Stents are passed through the body lumen in a collapsed state. At the point of an obstruction or other deployment site in the body lumen, the stent is expanded to an expanded diameter to support the lumen at the deployment site.

In certain designs, stents are open-celled tubes which are expanded by inflatable balloons at the deployment site. Other stents are so-called “self-expanding” stents. Self-expanding stents do not use balloons or other application of force to a collapsed stent to cause the expansion of the stent. An example of a self-expanding stent is a coil structure which is secured to a stent delivery device under tension in a collapsed state. At the deployment site, the coil is released so that the coil can expand to its enlarged diameter. Other self-expanding stents are made of so-called shape-memory metals such as nitinol. Such shape-memory stents experience a phase change at the elevated temperature of the human body. The phase change results in expansion from a collapsed state to an enlarged state.

A delivery technique for shape-memory alloy stents is to mount the collapsed stent on a distal end of a stent delivery system. Such a system would include an outer tubular member and an inner tubular member. The inner and outer tubular members are axially slideable relative to one another. The stent (in the collapsed state) is mounted surrounding the inner tubular member at its distal end. The outer tubular member (also called the outer sheath) surrounds the stent at the distal end.

Prior to advancing the stent delivery system through the body lumen, a guide wire is first passed through the body lumen to the deployment site. The inner tube of the delivery system is hollow throughout its length such that it can be advanced over the guide wire to the deployment site.

The combined structure (i.e., stent mounted on stent delivery system) is passed through the patient's lumen until the distal end of the delivery system arrives at the deployment site within the body lumen. The deployment system may include radio-opaque markers to permit a physician to visualize positioning of the stent under fluoroscopy prior to deployment.

At the deployment site, the outer sheath is retracted to expose the stent. The exposed stent is now free to expand within the body lumen. Following expansion of the stent, the inner tube is free to pass through the stent such that the delivery system can be removed through the body lumen leaving the stent in place at the deployment site.

In prior art devices, the stent may prematurely deploy as the outer tube is retracted. Namely, with the outer tube partially retracted, the exposed portion of the stent may expand resulting in the remainder of the stent being squeezed out of the outer tube. This can result in the stent being propelled distally beyond a desired deployment site. Also, once the stent partially unsheathed, it is sometimes determined that the stent placement needs to be adjusted. With existing systems, this is difficult since the stent has a tendency to force itself out of the sheath thereby making adjustments difficult. What is needed is a system that retains the stent on the catheter even when a majority of the stent has been exposed by retraction of the sheath. What is also needed is a system that allows a stent to be re-sheathed even after a majority of the stent has been exposed by retraction of the sheath.

It is an object of the present invention to provide improved structures for self-expandable implant delivery systems such as stent delivery systems.

SUMMARY OF THE INVENTION

One aspect of the present invention relates to a method for deploying a self-expandable implant with a deployment system. The deployment system includes a sheath for holding the implant in a compressed orientation. The implant includes an implant body that extends along an axis between first and second ends. The implant also includes an interlock surface that faces in an axial direction. The interlock surface is preferably located within 5 millimeters of the first end of the implant. The method is initiated by generating relative movement between the implant and the sheath to expose the implant. As the implant is exposed, the interlock surface of the implant is engaged by a retainer to prevent the implant from prematurely exiting the sheath. After the implant has been exposed beyond the interlock surface, the interlock surface is disengaged from the retainer by self-expanding the implant. Another aspect of the present invention relates to systems for practicing the above-described method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a stent delivery system according to the present invention;

FIG. 2A is an enlarged cross-sectional view of detail A of FIG. 1 with the stent in a compressed orientation;

FIG. 2B is an enlarged cross-sectional view of detail A of FIG. 1 with the stent in a deployed (i.e., expanded) orientation;

FIG. 3 is an enlarged cross-sectional view of detail B of FIG. 1;

FIG. 4 is an enlarged cross-sectional view of detail C;

FIG. 5 is a cross-sectional view of the inner and outer tubular members of the stent delivery system of FIG. 1 taken alongsection line5—5 of FIG. 3;

FIG. 6A is a plan view of a first stent having an interlock structure that interlocks with an interlock structure of a mating collar, the stent and the collar are shown cut longitudinally and laid flat with an axial separation between the stent proximal end and the mating collar;

FIG. 6B is the view of FIG. 6A with the stent proximal end and mating collar shown interlocked;

FIG. 6C is an end view of the stent of FIGS. 6A and 6B in its tubular configuration;

FIG. 7 is a laid flat, plan view of a second stent having an interlock structure that interlocks with an interlock structure of a mating collar, the collar includes rotational positioning indicators;

FIG. 8 is a laid flat, plan view of a third stent having an interlock structure that interlocks with an interlock structure of a mating collar, the collar includes rotational positioning notches;

FIG. 9 is a laid flat, plan view of a fourth stent having an interlock structure that interlocks with an interlock structure of a mating collar, the stent and the collar include a rotational alignment key and keyway;

FIG. 10 is a laid flat, plan view of a fifth stent having an interlock structure that interlocks with an interlock structure of a mating collar;

FIG. 11 is a laid flat, plan view of a sixth stent having an interlock structure that interlocks with an interlock structure of a mating collar;

FIG. 12 is a laid flat, plan view of a seventh stent having an interlock structure that interlocks with rectangular posts formed on an inner body of a catheter;

FIG. 13 is a laid flat, plan view of a eighth stent having an interlock structure that interlocks with an interlock structure of a mating collar;

FIG. 14A is a laid flat, plan view of a ninth stent having an interlock structure that interlocks with outwardly projecting line-like projections formed on the inner body of a catheter;

FIG. 14B shows the stent of FIG. 14A interlocked with the line-like projections;

FIG. 15A is a laid flat, plan view of a tenth stent having an interlock structure that interlocks with outwardly projecting posts formed on the inner body of a catheter; and

FIG. 15B shows the stent of FIG. 15A interlocked with the posts.

DETAILED DESCRIPTION

With reference now to the various drawing figures in which identical elements are numbered identically throughout, a description of a preferred embodiment of the present invention will now be provided.

With initial references to FIGS. 1-4, astent delivery system10 is shown. Thestent delivery system10 is for delivery of astent12 to a deployment site in a body lumen of a patient's body. By way of non-limiting, representative example, thestent12 may be a self-expanding, open-celled, tubular stent having a construction such as that shown in U.S. Pat. No. 6,132,461 and formed of a self-expanding, shape-memory or superelastic metal such as nitinol, or the like. Thestent12 may also be a coil stent or any other self-expanding stent. Thestent12 includes aproximal end12aand adistal end12b. Another representative stent is shown in U.S. patent application Ser. No. 09/765,725, filed Jan. 18, 2001 and entitled STENT, which is hereby incorporated by reference.

Thestent12 is carried on thestent delivery system10 in a collapsed (or reduced diameter) state as shown in FIG.2A. Upon release of thestent12 from the stent delivery system10 (as will be described), thestent12 expands to an enlarged diameter (see FIG. 2B) to abut against the walls of the patient's lumen in order to support patency of the lumen.

Thestent delivery system10 includes an inner tubular member14 (i.e., also referred to as an elongated member) and anouter tubular member16. Both of the inner and outertubular members14 and16 extend from proximal ends14a,16atodistal ends14b,16b.

The outertubular member16 is sized to be axially advanced through the patient's body lumen. Thetubular member16 is preferably sufficiently long for thedistal end16bto be placed near the deployment site in the patient's body lumen with theproximal end16aremaining external to the patient's body for manipulation by an operator. By way of example, the outer tubular member16 (also referred to as a sheath) may be a braid-reinforced polyester of tubular construction to resist kinking and to transmit axial forces along the length of thesheath16. The outertubular member16 may be of widely varying construction to permit varying degrees of flexibility of the outertubular member16 along its length.

As shown in FIG. 3, theproximal end16aof the outertubular member16 is bonded to amanifold housing20. Themanifold housing20 is threadedly connected to alock housing22. Astrain relief jacket24 is connected to themanifold housing20 and surrounds the outertubular member16 to provide strain relief for the outertubular member16.

Theinner tubular member14 is preferably formed of nylon but may be constructed of any suitable material. As shown in FIG. 2B, theinner tubular member14 defines astent attachment location26. Theinner tubular member14 also includesmarkers27,28 that are attached to an outer surface of the inner tubular member14 (e.g., by techniques such as adhesive, heat fusion, interference fit or other techniques). Theattachment location26 is positioned between themarkers27,28. The radio-opaque markers27,28 permit a physician to accurately determine the position of thestent attachment location26 within the patient's lumen under fluoroscopic visualization. As will be described later in the specification, in some embodiments, at least one of themarkers27,28 forms a collar including a geometry that interlocks with thestent12 to prevent axial movement of thestent12 relative to the inner tubular member during transport and deployment of thestent12.

A tapered and flexibledistal tip member30 is secured to thedistal end14bof theinner tubular member14. The highly flexibledistal tip member30 permits advancement of thestent deployment system10 through the patient's lumen and minimizes trauma to the walls of the patient's lumen.

As best shown in FIGS. 3 and 4, theinner tube14 passes through both themanifold housing20 and lockhousing22. Astainless steel jacket32 surrounds and is bonded to theinner tubular member14.

At the inner tubeproximal end14a, aport housing34 is bonded to thestainless steel jacket32. Theport housing34 has a taperedbore36 aligned with aninner lumen38 of thetubular member14. Theinner lumen38 extends completely through theinner tubular member14 so that theentire delivery system10 can be passed over a guide wire (not shown) initially positioned within the patient's lumen. Opposing surfaces of the inner and outertubular members14 and16, define a first lumen40 (best seen in FIG.5). As described in U.S. patent application Ser. No. 09/765,719 filed on Jan. 18, 2001 and entitled STENT DELIVERY SYSTEM WITH SPACER MEMBER, which is hereby incorporated by reference, splines18 can be provided between the inner and outertubular members14 and16.

As shown in FIG. 3, themanifold housing20 carries anadmission port42 for injecting a contrast media into the interior of themanifold housing20. The interior of themanifold housing20 is in fluid flow communication with thefirst lumen40. Discharge ports41 (shown in FIGS. 2A and 2B) are formed through the outertubular member16 to permit contrast media to flow from thefirst lumen40 into the patient's body lumen.

As shown in FIG. 3, an O-ring44 surrounds thestainless steel jacket32 between themanifold housing20 and lockhousing22. Upon threaded connection of themanifold housing20 to thelock housing22, the O-ring44 compresses against thestainless steel jacket32 in sealing engagement to prevent contrast media from flowing in any path other than through thefirst lumen40.

As shown in FIGS. 1 and 3, thelock housing22 carries a threaded locking member (or lock nut)46 which can be turned to abut thestainless steel jacket32. Thelock nut46 can be released to free the stainless steel jacket to move axially. According, when thelock nut46 engages thejacket32, the jacket32 (and attached inner tubular member14) cannot move relative to thelock housing22,manifold housing20 or the outertubular member16. Upon release of thelock nut46, theinner tubular member14 and outertubular member16 are free to slide axially relative to one another between a transport position and a deploy position.

First andsecond handles48,50 are secured to thelock housing22 andjacket32, respectively. In the transport position (shown in FIG.2A), thehandles48,50 are spaced apart and the distal end of the outertubular member16 forms a sheath that covers thestent attachment location26 to prevent premature deployment of thestent12. When thehandle48 is pulled rearwardly toward thehandle50, the outertubular member16 slides rearwardly or proximally relative to theinner tubular member14. Preferably, the outertubular member16 slides rearwardly a distance sufficient to fully expose thestent attachment location26 and permit thestent12 to freely expand toward its fully expanded diameter (see FIG.2B). After such expansion, the stent delivery system can be proximally withdrawn through the expanded stent and removed.

As shown in FIG. 3, thefirst handle48 is rotatably mounted on aflange22aof thelock housing22. Thefirst handle48 surrounds thestainless steel jacket32 and is freely rotatable about the longitudinal axis of thejacket32 and freely rotatable about theflange22a. Thefirst handle48 is axially affixed to thelock housing22 such that axial forces applied to thefirst handle48 are transmitted through thelock housing22 andmanifold housing20 to the outertubular member16 to axially move theouter tubular16. However, rotary action of thefirst handle48 about the axis of thestainless steel jacket32 is not transmitted to thehousings20,22 or to the outertubular member16 by reason of the free rotation of thefirst handle48 onflange22a.

As shown in FIG. 4, thesecond handle50 is mounted on ananchor52 that is bonded to thestainless steel jacket32 through any suitable means (such as by use of adhesives). Theanchor52 includes aflange52athat is radial to the axis of thestainless steel jacket32. Thesecond handle50 is mounted on theflange52aand is free to rotate on theanchor52 about the axis of thestainless steel jacket32. However, axial forces applied to thehandle50 are transmitted to thestainless steel jacket32 which, being bonded to theinner tubular member14, results in axial movement of theinner tubular member14.

With the handle construction described above, relative axial movement between thehandles48,50 results in relative axial movement between the inner and outertubular members14,16. Rotational movement of either of thehandles48,50 does not affect rotational positioning of the inner or outertubular members14,16 and does not affect axial positioning of the inner andouter tubes14,16.

The free rotation of thehandles48,50 results in ease of use for a physician who may position his or her hands as desired without fear of interfering with any axial positioning of the inner and outertubular members14,16. The spacing between thehandles48,50 is equal to the stroke between the transport position and the deploy position of thetubular members14,16. As a result, the spacing permits the operator to have ready visual indication of the relative axial positioning between the inner and outertubular members14,16. This relative axial positioning can be fixed by engaging thelock nut46. In any such positioning, contrast media can be injected through theadmission port42 into thechamber40 with the contrast media flowing out of theside ports41 into the body lumen to permit visualization under fluoroscopy.

With stent deployment systems having premounted stents of various axial lengths, the positioning of thesecond handle50 on thestainless steel jacket32 can be selected at time of assembly so that a spacing S (see FIG. 1) between thehandles48,50 corresponds to the length of thestent12 carried on the stent deployment system. For example, in a preferred embodiment, the spacing S is about 10 millimeters longer than the deployed length of the stent. Accordingly, the user will know that the outertubular member16 has been fully retracted when thehandles48,50 have been pushed completely together to completely release thestent12. Also, the freely rotatable handles48,50 are easy to hold from any angle without slippage. Thelock nut46 ensures that thestent12 will not deploy prematurely.

A concern with existing delivery systems for self-expanding stents is control of stent delivery. For example, due to their elastic characteristics, self-expanding stents have a tendency to propel themselves axially outwardly from their restraining sheaths before the sheaths have been completely retracted. When this occurs, control of stent placement is compromised since the stent may overshoot the desired deployment site. Further, once the stent has been completely deployed, subsequent adjustment of the stent deployment location can be difficult because re-sheathing typically cannot be readily accomplished.

To address the above concerns, thedelivery system10 is preferably equipped with an interlock configuration that constrains relative axial movement between thestent12 and theinner tube14 until after thesheath16 has been fully retracted. For example, when thestent12 is mounted on theinner tube14 and restrained in the compressed orientation by thesheath16 as shown in FIG. 2A, a first interlock geometry (e.g.,male interlock structures82 as shown in FIG. 2A) located at the proximal end of thestent12 interlocks with a second interlock geometry (e.g.,female interlock structures84 as shown in FIG. 2A) defined by the proximal marker27 (also referred to as a collar). The interlock geometries remain interlocked to constrain axial movement of thestent12 until after the sheath has been retracted beyond a predetermined location (e.g., theproximal-most end12aof the stent12). When thesheath12 has been retracted beyond the predetermined location, the interlock geometry of thestent12 is allowed to expand. As the interlock geometry of the stent expands, the interlock geometry of the stent disengages from the interlock geometry of themarker27 thereby allowing theinner tube14 of the catheter to be moved axially relative to the stent without interference from the interlock geometries.

FIGS. 6A and 6B illustrate theproximal end12aof thestent12 in relation to themarker27 located at the proximal end of theattachment location26. In FIGS. 6A and 6B, thestent12 and themarker27 have been cut longitudinally and laid flat. Thestent12 has a length L and a circumference C. In FIG. 6A, themarker27 and thestent12 are shown disengaged from one another. In FIG.6B marker27 and thestent12 are shown interlocked.

Referring to FIG. 6A, thestent12 includes a plurality of struts86 (i.e., reinforcing members). A number of the plurality of struts, e.g. twelve, define a cell17 (also shown in FIG.2B). Thestent12 is made up of a plurality ofinterconnected cells17. Still referring to FIG. 6A, each cell has a compressed or collapsed cell length Lc. At least some of thestruts86 of thecells17 have free terminal ends that define the proximal and distal ends12aand12bof thestent12. Male interlock structures82 (i.e., keys) are provided at the free terminal ends of thestruts86. As shown in FIG. 6A, themale interlock structures82 include enlargements in the form of circular projections that extend a distance d from the free terminal ends of thestruts86. In the preferred embodiment, the distance d that themale interlock structures82 extend from the free terminal ends of thestruts86 is less than the collapsed cell length Lc of thecells17. Thus, themale interlock structures82 are within at most one collapsed cell length Lc of thecells17.

The circular projections includeinterlock portions88 that project outwardly from thestruts86 in a circumferential direction (i.e., in a direction coinciding with the circumference C of the stent12). Theinterlock portions88 include interlock surfaces90 that face in an axial direction. The phrase “face in an axial direction” will be understood to mean that least a vector component of thesurface90 is perpendicular with respect to a longitudinal axis A—A of thestent12. Thus, thesurface90 need not be completely perpendicular relative to the longitudinal axis of thestent12 to be construed as facing in an axial direction. In other words, a surface aligned at oblique angle relative to the longitudinal axis of thestent12 shall also be construed as facing in an axial direction since such surface has a vector component that is perpendicular relative to the longitudinal axis of the stent.

As best shown schematically in FIG. 6C, themale interlock structures82 are preferably positioned within a region defined between an inner diameter D1 and an outer diameter D2 of thestent12. Preferably, at least portions of the interlock surfaces90 are located within 5 millimeters of theproximal end12aof thestent12. More preferably, at least portions of the interlock surfaces90 are located within 3 millimeters of theproximal end12aof thestent12. Most preferably, at least portions of the interlock surfaces90 are located within 2 millimeters of theproximal end12aof thestent12.

Still referring to FIGS. 6A and 6B, themarker27 has an axialdistal edge29 facing theproximal end12aofstent12. Female interlock structures84 (i.e., sockets, openings, keyways, etc.) are defined by themarker27 adjacent theedge29. Thefemale interlock structures84 are configured to have a complimentary mating geometry with respect to themale interlock structures82 of thestent12. For example, similar to themale interlock structures82, thefemale interlock structures84 are shown having generally rounded or circular shapes. Each of thefemale interlock structures84 includes interlock surfaces92 that face in an axial direction.

The geometry of thefemale interlock structures84 is selected to mate with the predetermined geometry of the stentproximal end12asuch that thestent12 and themarker27 can be axially coupled or interlocked when thestent12 is compressed at the mountinglocation26. When the male andfemale interlock structures82 and84 are interlocked, the interlock surfaces90 and92 oppose and circumferentially overlap one another (see FIG. 6B) such that the stent is restricted from distal movement relative to themarker27.

With the specific embodiment shown, thestent12 andcollar27 are rotary coupled such that thestent12 andcollar27 are restricted from relative rotary motion (i.e., about axis A—A) when thestent12 is in the collapsed state. The predetermined stent geometry of theinterlock structures82 and the complementary mating geometry of thecollar27 do not restrict relative radial motion. Namely, as the self-expandingstent12 expands radially, themale interlock structures82 are free to radially move out of thefemale interlock structures84. After such motion, thestent12 is no longer coupled to thecollar27 and thestent12 andcollar27 are free to move axially, radially or transversely to one another.

With the embodiment thus described, the mating features of thestent12 andcollar27 prevent premature discharge of thestent12 from astent attachment location26. As theouter sheath16 is retracted, the sheathdistal end16bexposes thedistal end12bof thestent12. At this point, the exposeddistal end12bof thestent12 is free for limited expansion restrained by the remainder of thestent12 being covered by thesheath16 and by the attachment of the stentproximal end12ato the proximalradiopaque marker27.

Further retraction of thesheath16, permits still further expansion of thestent12. As the sheathdistal end12bapproaches the stentproximal end12a, the expansion of the stent material tends to urge thestent12 to squeeze out of the small portion of thesheath16 now covering thestent12. However, this propensity is overcome by the attachment of the stentproximal end12ato thecollar27 since any such ejection of thestent12 would require axial separation of thestent12 andcollar27. Such movement is prevented by themale interlock structures82 and thefemale interlock structures84.

Therefore, as long any portion of thesheath16 overlies the male andfemale interlock structures82 and84, theproximal end12aof thestent12 cannot expand and cannot axially move away from thecollar27. Accordingly, thestent12 is not released from theattachment location26 until the physician has fully retracted thesheath16 with the sheathdistal end16bretracted proximal to the proximal end ofstent attachment location26. The sheathdistal end16bis provided with aradiopaque marker16b′ (shown in FIGS. 2A and 2B) to permit visualization of the relative position of the sheathdistal end12band theradiopaque markers27,28 of thestent attachment location26.

With the structure and operation thus described, the physician has greater control of the release of thestent12. More accurate stent positioning is attained. As long as even a small portion of thesheath16 is not fully retracted (e.g., at least 1 mm extends distally to theproximal end12aof the stent12) the axial position of thestent12 can be adjusted by advancing or retracting theinner tubular member14. Also, as long as a small portion of thesheath16 remains covered by the sheath16 (e.g., at least 1 mm), thestent12 can be readily re-sheathed by moving thesheath16 in a distal direction.

In the embodiment of FIGS. 6A and 6B, the female andmale interlock structures82 and84 have complementary mating geometries. It will be appreciated that in alternative embodiments, the female and male interlock structures need not have complementary/identical shapes. Instead, to provide an interlock, it is only necessary for a portion of the male interlock to be received in the female interlock such that mechanical interference or overlap between the interlocks prevents the interlocks from being axially separated. This can be accomplished without having identical mating shapes.

As described above, theinterlock structure84 of theinner tube14 is provided on the proximalradiopaque marker27. It will be appreciated that theinterlock structure84 need not be the same element as the radiopaque marker but could be a separate part. As a separate part, the interlock structure could be integrally formed/connected with the exterior of theinner tube14, connected to the outer surface of the inner tube by conventional techniques (e.g., adhesive, fasteners, fusion bonding, etc.), or be connected to the outer surface of theinner tube14 by one or more intermediate members. Further, the embodiment of FIGS. 6A and 6B shows that the interlock between thestent12 and thetube14 is provided at theproximal end12aof thestent12b. It will be appreciated that for certain embodiments, the interlock between theinner tube14 and thestent12 can be provided at thedistal end12bof the stent12 (e.g., for a distally retractable sheath). Moreover, while the embodiment of FIGS. 6A and 6B shows interlock structures provided at all of the proximal ends of thestruts86, the invention is not so limited. For example, in some embodiments, only some of thestruts86 may include interlock structures. While in certain embodiments it may be desirable to use only one interlock structure at the end of thestent12, it is preferable to use at least two separate/discrete interlock structures uniformly spaced about the circumference of the stent. It is more preferable to use at least 4 separate/discrete interlock structures that are preferably uniformly spaced about the circumference of the stent.

Thecollar27 may be provided with indicia to indicate to a physician the position of the collar27 (and hence the stent12) when the combination is in a patient's vessel and is being visualized under fluoroscopy. In the embodiment of FIGS. 6A and 6B, the indicia is shown ascutouts15 in thecollar27. FIG. 7 shows acollar27′ having indicia in the form ofproximal projections15′ off of the proximal edge of thecollar27′. FIG. 8 shows acollar27″ having indicia in the form oftriangular notches15″ defined at the proximal edge of thecollar27″. In the embodiments shown, theindicia15,15′ and15″ are spaced apart circumferentially on theirrespective collars27,27′ and27″ so that the indicia are 180 degrees apart.

In the embodiment of FIGS. 6A and 6B, the pattern and shape of themale interlock structures82 and thefemale interlock structures84 are symmetrical about the stent axis A—A. As a result, thestent12 can be affixed to thecollar27 in any one of a plurality of rotary alignments about axis A—A.

FIG. 9 illustrates an embodiment of acollar127 andstent112 where the symmetrical pattern is interrupted. In the example of FIG. 9, a singleunique key117 is provided (which, in the example shown, has a square geometry compared to the circular geometry of remaining male interlock structures182). Similarly, thecollar127 has aunique keyway117ato mate with theunique key117. As a result, thestent112 can only be affixed to thecollar127 in one rotary alignment.

In all of the above embodiments, once the position of a stent is fixed to a collar, a non-symmetrical stent feature (e.g., an opening for placement at a bifurcation in a vessel) can be aligned with the indicia (or, if desired, a single indicia can be provided on the collar). Therefore, a physician can easily visualize the position of any non-symmetrical stent feature.

FIG. 10 illustrates an embodiment of astent212 and radio-opaque collar227 having another interlock configuration. Thecollar227 hascircumfential slots228 for assisting in adhesively bonding thecollar227 to the outer surface of theinner tube14. Thestent212 has proximal anddistal ends212aand212b. The stent also includes proximal end struts286ahaving free ends at whichmale interlock structures282 are formed. Themale interlock structures282 are formed by notches cut into the proximal end struts286a. Themale interlock structures282 include axially facing interlock surfaces290 that face in a distal direction. Preferably, thesurfaces290 are located within 5 millimeters of theproximal end212aof thestent212.

Thecollar227 includesfemale interlock structures284 in the form of sockets. The sockets are partially defined by projections adapted to fit within the notches cut into the proximal end struts286a. The projections define axially facing interlock surfaces292 that face in a proximal direction. When the male andfemale interlock structures282 and284 are interlocked, thesurfaces290 and292 oppose one another to prevent themale interlock structures282 from being axially withdrawn from thefemale interlock structures284.

FIG. 11 illustrates an embodiment of astent312 and radio-opaque collar327 having another interlock configuration. Thecollar327 hascircumfential slots328 for assisting in adhesively bonding thecollar327 to the outer surface of theinner tube14. Thestent312 has proximal anddistal ends312aand312b. The stent also includes proximal end struts386ahaving free ends at whichmale interlock structures382 are formed. Themale interlock structures382 are formed by enlarged heads (i.e., protuberances or keys) located at the ends of the end struts386a. Themale interlock structures382 include axially facing interlock surfaces390 that face in a distal direction. Preferably, thesurfaces390 are located within 5 millimeters of theproximal end312aof thestent312. Thecollar327 includesfemale interlock structures384 in the form of sockets. Thefemale interlock structures384 include axially facing interlock surfaces392 that face in a proximal direction. When the male andfemale interlock structures382 and384 are interlocked, thesurfaces390 and392 oppose one another to prevent themale interlock structures382 from being axially withdrawn from thefemale interlock structures384.

FIG. 12 illustrates an embodiment of astent412 includingfemale interlock structures484. Thefemale interlock structures484 preferably include distally facing interlock surfaces492 located within 5 mm of aproximal end412aof thestent412. Thefemale interlock structures484 are sized to receivemale interlock structures482 in the form of rectangular posts. Preferably, the posts are connected to the outer surface of the inner tube14 (e.g., integrally or otherwise). The posts define proximally facing interlock surfaces490. When the female andmale interlock structures484 and482 are coupled, thesurfaces490 and492 engage each other to prevent distal movement of thestent412 relative to the posts.

FIG. 13 illustrates an embodiment of astent512 includingmale interlock structures582 in the form of hooks. Themale interlock structures582 preferably include distally facing interlock surfaces590 located within 5 mm of aproximal end512aof thestent512. Themale interlock structures582 are sized to fit withinfemale interlock structures584 defined by acollar527. Thefemale interlock structures584 define proximally facing interlock surfaces592. When the female andmale interlock structures584 and582 are coupled, thesurfaces590 and592 engage each other to prevent distal movement of thestent512 relative to thecollar527.

FIGS. 14A and 14B illustrate an embodiment of astent612 includingfemale interlock structures684 in the form of longitudinal slots between or within struts. Thefemale interlock structures684 preferably include distally facing interlock surfaces692 (e.g., defined by the proximal ends of the slots) located within 5 mm of aproximal end612aof thestent612. Thefemale interlock structures684 are sized to receivemale interlock structures682 in the form of linear posts. Preferably, the posts are connected to the outer surface of the inner tube14 (e.g., integrally or otherwise). The posts define proximally facing interlock surfaces690 (e.g., at the proximal ends of the posts). When the female andmale interlock structures684 and682 are coupled as shown in FIG. 14B, thesurfaces690 and692 engage each other to prevent distal movement of thestent612 relative to the posts.

FIGS. 15A and 15B illustrate an embodiment of astent712 includingfemale interlock structures784 in the form of circular openings defined through enlarged strut ends of thestent712. Thefemale interlock structures784 preferably include distally facing interlock surfaces792 located within 5 mm of aproximal end712aof thestent712. Thefemale interlock structures784 are sized to receivemale interlock structures782 in the form of cylindrical posts or pins. Preferably, the posts are connected to the outer surface of the inner tube14 (e.g., integrally or otherwise). The posts define proximally facing interlock surfaces790. When the female andmale interlock structures784 and782 are coupled as shown in FIG. 15B, thesurfaces790 and792 engage each other to prevent distal movement of thestent712 relative to the posts.

While the various embodiments of the present invention have related to stents and stent delivery systems, the scope of the present invention is not so limited. For example, while particularly suited for stent delivery systems, it will be appreciated that the various aspects of the present invention are also applicable to systems for delivering other types of self-expandable implants. By way of non-limiting example, other types of self-expanding implants include anastomosis devices, blood filters, grafts, vena cava filters, percutaneous valves, or other devices. Also, while it is preferred for the interlocks of the present invention to be within 5 millimeters of an end of their corresponding implant to enhance deployment control, larger spacings could be used for certain applications.

It has been shown how the objects of the invention have been attained in a preferred manner. Modifications and equivalents of the disclosed concepts are intended to be included within the scope of the claims.

Claims (42)

What is claimed is:

1. A stent delivery system for delivering a stent to a deployment site in a body lumen of a patient's body, said stent delivery system comprising:

an elongated, flexible, hollow outer tubular member having a distal end and a proximal end;

an elongated, flexible, inner tubular member having a distal end and a proximal end;

said outer tubular member sized to be passed through said body lumen with said distal end advanced to said deployment site and with said proximal end external to said body for manipulation by an operator;

said inner member sized to be received within said outer tubular member with said inner member and said outer tubular member axially slideable relative to one another between a transport position and a deploy position;

said inner tubular member having a stent attachment location at said distal end of said inner tubular member, said stent attachment location having a proximal end and a distal end, said stent attachment location covered by said outer tubular member when said inner and outer tubular members are in said transport position, said stent attachment location exposed when said inner and outer tubular members are in said deploy position, sliding relative motion between said inner member and said outer tubular member from said transport position to said deploy position exposing first said distal end of said stent attachment location, an intermediate portion of said stent attachment location and then said proximal end of said stent attachment location;

a stent carried at said stent attachment location with a distal and proximal ends of said stent at said distal and proximal ends, respectively, of said stent attachment location;

said proximal end of said stent including a stent geometry having at least one male interlock structure that interlocks with said inner member to restrict said stent from axial movement relative to said inner member until said distal end of said outer tubular member moves proximally to said proximal end of said stent attachment location as said inner and outer members move toward said deploy position; and

wherein the stent includes cell defining structures that define cells having a cell length, and wherein the inner member interlocks with the stent at an interlock location external of the cells, the interlock location being positioned not more than one cell length away from the cells.

2. A stent delivery system according toclaim 1 wherein said proximal end of said stent releasably secured to said inner member to be restricted from rotary movement relative thereto until said distal end of said outer tubular member moves proximally to said proximal end of said stent attachment location as said inner and outer members move toward said deploy position.

3. A stent delivery system according toclaim 2 wherein said inner member at said proximal end of said stent attachment location has a complimentary mating geometry to that of said stent geometry to restrict relative rotary movement between said proximal end of said stent and said inner member at said proximal end of said stent attachment location while permitting unrestricted radial expansion of said proximal end of said stent at said proximal end of said stent attachment location after said distal member of said outer tubular member has moved to expose said proximal end of said stent attachment location.

4. A stent delivery system according toclaim 2 wherein said stent geometry is asymmetrical for said proximal end of said stent to be mated to said proximal end of said stent attachment location in a predetermined rotary alignment.

5. A stent delivery system according toclaim 2 wherein said stent geometry is symmetrical for said proximal end of said stent to be mated to said proximal end of said stent attachment location in any one of a plurality of rotary positions.

6. A stent delivery system according toclaim 1 wherein said inner member at said proximal end of said stent attachment location has a complimentary mating geometry to that of said stent geometry to restrict relative axial movement between said proximal end of said stent and said inner member at said proximal end of said stent attachment location while permitting unrestricted radial expansion of said proximal end of said stent at said proximal end of said stent attachment location after said distal member of said outer tubular member has moved to expose said proximal end of said stent attachment location.

7. A stent delivery system according toclaim 6 wherein said complimentary mating geometry is formed in a radiopaque material at said proximal end of said attachment location.

8. A stent delivery system according toclaim 6 wherein said complimentary mating geometry is formed in a collar positioned said proximal end of said stent attachment location.

9. A stent delivery system according toclaim 1 wherein said stent geometry is asymmetrical for said proximal end of said stent to be mated to said proximal end of said stent attachment location in a predetermined rotary alignment.

10. A stent delivery system according toclaim 9 further comprising a radiopaque indicator indicating a rotary position of said stent.

11. A stent delivery system according toclaim 9 wherein said proximal end of said stent attachment location includes a radiopaque indicator indicating a rotary position of said attachment location.

12. A stent delivery system according toclaim 1 wherein said stent geometry is symmetrical for said proximal end of said stent to be mated to said proximal end of said stent attachment location in any one of a plurality of rotary positions.

13. A stent delivery system according toclaim 1 wherein said distal end of said outer tubular member has a radiopaque marking.

14. A stent delivery system according toclaim 1 wherein said inner tubular member is hollow to track over a guide wire.

15. An implant delivery system comprising:

a catheter including an elongated member having an implant mounting location;

an expandable implant mounted on the elongated member at the implant mounting location, the implant being expandable from a compressed orientation to an expanded orientation, the implant including first and second ends, and a male interlock structure;

a sheath mounted on the elongated member, the sheath being positionable in a transport position in which the sheath covers the implant mounted at the implant mounting location, the sheath also being positionable in a deploy position in which the implant is exposed;

a radio-opaque marker positioned adjacent the implant mounting location, the radio-opaque marker being made of a radio-opaque material and having a female interlock structure;

wherein the male interlock structure of the implant interlocks with the female interlock structure of the radio-opaque marker to constrain axial movement of the implant relative to the elongated member when the implant is at least partially within the sheath.

16. The implant delivery system ofclaim 15, wherein the implant comprises a stent.

17. The implant delivery system ofclaim 15, wherein at least a portion of the male interlock structure is positioned within 5 millimeters of the first end of the implant.

18. The implant delivery system ofclaim 15, wherein the first end of the implant is a proximal end of the implant.

19. The implant delivery system ofclaim 15, wherein the implant includes a plurality of male interlock structures having at least portions positioned within 5 millimeters of the first end, and wherein the radio-opaque marker includes a plurality of female interlock structures for interlocking with the male interlock structures.

20. The implant delivery system ofclaim 15, wherein the male interlock structure includes an enlargement positioned at the first end of the implant.

21. The implant delivery system ofclaim 20, wherein the implant includes a plurality of enlargements at the first end of the implant.

22. The implant delivery system ofclaim 20, wherein the male interlock structure includes a circumferential projection positioned at the first end of the implant.

23. The implant delivery system ofclaim 22, wherein the implant includes a plurality of the circumferential projections at the first end of the implant.

24. A stent delivery system comprising:

a catheter including an elongated body having a stent mounting location;

an expandable stent mounted on the elongated body at the stent mounting location, the stent being expandable from a compressed orientation to an expanded orientation, the stent including first and second ends;

a sheath mounted on the elongated body, the sheath being positionable in a transport position in which the sheath covers the stent mounted at the stent mounting location, the sheath also being positionable in a deploy position in which the stent is exposed;

the stent including a plurality of struts at least some of which have free ends defining the first end of the stent, the free ends being adjacent cell defining regions of the stent, the cell defining regions defining cells having a cell length, the stent also including at least two male interlock structures positioned not more than one cell length away from the cells; and

the elongated body including female interlock structures that receive the male interlock structures to constrain axial movement of the stent relative to the elongated body when the stent is at least partially within the sheath.

25. The stent delivery system ofclaim 24, wherein the elongated body includes a radio-opaque marker positioned adjacent to the stent mounting location, and wherein the marker defines the female interlock structures.

26. The stent delivery system ofclaim 24, wherein the first end of the stent is a proximal end of the stent.

27. The stent delivery system ofclaim 24, wherein the male interlock structures are rounded enlargements.

28. The stent delivery system ofclaim 24, wherein the male interlock structures are positioned exclusively between inner and outer diameters of the stent.

29. The stent delivery system ofclaim 24, wherein the male interlock structures are uniformly spaced about a circumference of the stent.

30. The stent delivery system ofclaim 24, wherein the stent includes at least four of the male interlock structures.

31. The stent delivery system ofclaim 24, wherein the male interlock structures are integral male interlock structures located at the free ends of the struts.

32. An implant delivery system comprising:

a catheter including an elongated member having an implant mounting location;

an expandable implant mounted on the elongated body at the implant mounting location, the implant being expandable from a compressed orientation to an expanded orientation, the implant including first and second ends;

a sheath mounted on the elongated member, the sheath being positionable in a transport position in which the sheath covers the implant mounted at the implant mounting location, the sheath also being positionable in a deploy position in which the implant is exposed;

the implant including a male interlock structure having an enlargement defining a circumferential projection positioned at the first end of the implant, and the elongated body including a female interlock structure adapted to receive the male interlock structure when the implant is in the compressed orientation, the male and female interlock structures interlocking to constrain axial movement of the implant relative to the elongated member when the implant is at least partially within the sheath;

at least a portion of the male interlock structure being positioned within 5 millimeters of the first end of the implant; and

wherein the elongated body includes a radio-opaque marker positioned adjacent to the implant mounting location, and wherein the marker defines the female interlock structure.

33. The implant delivery system ofclaim 32, wherein the implant includes a plurality of the circumferential projections at the first end of the implant.

34. A stent delivery system comprising:

a catheter including an elongated member having a stent mounting location;

an expandable stent mounted on the elongated body at the stent mounting location, the stent being expandable from a compressed orientation to an expanded orientation, the stent including first and second ends;

a sheath mounted on the elongated body, the sheath being positionable in a transport position in which the sheath covers the stent mounted at the stent mounting location, the sheath also being positionable in a deploy position in which the stent is exposed;

the stent including a plurality of struts at least some of which have free ends defining the first end of the stent, the stent also including at least two male interlock structures having rounded enlargements, the male interlock structures being positioned at the free ends of the struts adjacent the first end of the stent, the free ends being adjacent cell defining regions of the stent; and

the elongated body including female interlock structures that receive the male interlock structures to constrain axial movement of the stent relative to the elongated member when the stent is at least partially within the sheath.

35. A stent delivery system comprising:

a catheter including an elongated member having a stent mounting location;

an expandable stent mounted on the elongated member at the stent mounting location, the stent being expandable from a compressed orientation to an expanded orientation, the stent including a stent body having first and second ends;

a sheath mounted on the elongated member, the sheath being positionable in a transport position in which the sheath covers the stent mounted at the stent mounting location, the sheath also being positionable in a deploy position in which the stent is exposed;

the stent body having a cell defining region including a plurality of cells, each cell having a compressed cell length, one of the first and second ends of the stent body including at least one integral male interlock structure, the integral male interlock structure being located not more than one compressed cell length away from the cell defining region of the stent body; and

the elongated member including female interlock structures that receive the male interlock structures to constrain axial movement of the stent relative to the elongated member when the stent is at least partially within the sheath.

36. The stent delivery system ofclaim 35 wherein the stent body defines an inner diameter and an outer diameter, the male interlock structure being located in a region defined between the inner diameter and the outer diameter.

37. The stent delivery system ofclaim 36 wherein the male interlock structure has a cross-sectional curvature about a longitudinal axis of the stent.

38. The stent delivery system ofclaim 35 wherein the stent body includes a plurality of integral male interlock structure.

39. A stent delivery system comprising:

a catheter including an elongated body having a stent mounting location;

an expandable stent mounted on the elongated body at the stent mounting location, the stent being expandable from an undeployed orientation to a deployed orientation, the stent including first and second ends and a cell defining region located between the first and second ends, the cell defining regions defining cells each having a cell length, the stent also including at least one or more male interlock structures positioned not more than one cell length away from the cell defining region; and

the elongated body including at least one or more female interlock structures that receive the one or more male interlock structures to constrain axial movement of the stent relative to the elongated body.

40. The stent delivery system ofclaim 39, wherein the expandable stent includes at least two male interlock structures positioned not more than one cell length away from the cell defining region, and wherein the elongated body includes at least two female interlock structures that receive the at least two male interlock structures.

41. A stent delivery system comprising:

a catheter including an elongated member having a stent mounting location;

an expandable stent mounted on the elongated body at the stent mounting location, the stent being expandable from an undeployed orientation to a deployed orientation, the stent including first and second ends, the stent also including one or more male interlock structures each having a rounded enlargement, the one or more male interlock structures being positioned at the first end of the stent; and

the elongated body including one or more female interlock structures that receive the one or more male interlock structures to contratin axial movement of the stent relative to the elongated member.

42. The stent delivery system ofclaim 41, wherein the expandable stent includes at least two male interlock structures each having a rounded enlargement, and wherein the elongated body includes at least two female interlock structures that receive the at least two male interlock structures.

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